From Big Medical Encyclopedia

SYNOVIAL FLUID (synovia; synonym synovia) — the viscous, transparent liquid filling joint cavities, synovial vaginas of sinews and synovial (mucous) bags. Reminds ovalbumin.

By origin Page. is dialyzate blood plasma (see). Along with the chemical substances inherent in a blood plasma, it includes a specific component — hyaluronic to - that (see. Hyaluronic acids ). Concentration of glucose in the Village. slightly lower than its concentration in blood. Proteins of Page. on electrophoretic and immunological indicators are identical to proteins of a blood plasma but total concentration of protein and a ratio of albumine and globulins considerably differ from those in a blood plasma; in the Village. there is no fibrinogen. An indicator of pH of synovial fluid — 7,768, in comparison with pH of a blood plasma it is shifted in the alkaline party. Thanks to viscosity of Page., and also optimal conditions for movements in a joint or a tendinous vagina are created to elasticity and elasticity of a cartilage and a sinew. Viscosity of Page. it is caused by existence in it hyaluronic to - you, produced by fibroblastichesky siioviotsita (V-cells) synovial membrane (see).

Normal from a cavity of a knee joint it is possible to receive 1 — 2 ml of liquid, at synovites (see) — to 100 ml and more. Normal in 1 ml of Page. from 15 to 200 cells contain, at diseases (e.g., a pseudorheumatism) the quantity of cells in the same volume of liquid (cytosis) increases to several tens of thousands. Cellular structure of Page. it is normal rather constant and is characterized by a certain ratio of separate types (classes) of cells, among to-rykh are present as blood cells (lymphocytes, monocytes, macrophages, plasmocytes), and the cells coming to a joint cavity from a synovial membrane — macrophagic sinoviotsita and fabric macrophages (histiocytes). Cellular structure patholologically changed Page. it is characterized along with increase in a cytosis change of a ratio of separate types of cells.

On the basis of modern data the sinoviotsitogramma characterizing quantitative distribution of cells of Page is offered. normal, its changes are also shown at a number of diseases of joints. Sinoviotsitogramma reflects activity of local inflammatory process and in total with other parameters of Page. (including immunological) can serve one of important tests for differential diagnosis of diseases of joints (e.g., a pseudorheumatism, an osteoarthrosis, etc.), and also dynamic overseeing as a condition of joints in the course of treatment. Research of punctates of Page., called by «a liquid biopsy of joints», widely is implemented into arthrologic practice.

Page. carries out locomotory, metabolic, barrier (protective) functions. Locomotory function is connected with participation of Page. as the lubricant of cartilaginous surfaces of a mobile joint protecting them from damage (see. Joints ). Rich with water, proteins and hyaluronic to - that Page. forms in a joint crack the tire-tread film covering the surfaces of a joint cartilage, and also dense conglomerates of hyalrunate in undulations of cartilaginous surfaces and liquid with Page. between them. Metabolic function of Page. consists in its participation in exchange processes between contents of a joint and a vascular bed of a synovial membrane (see), in providing a trophicity of an avascular joint cartilage. Barrier (protective) function is connected with participation of enzymes of Page. and its immunocompetent cells (together with those of a synovial membrane) in absorption, dissolution, inhibition of alien cells and substances, including autoantigens. Immunol. reactivity of Page. it is provided with cellular elements and, first of all, T - and V-lymphocytes (see. Immunekompetentny cells ) and the fabric macrophages (see) and also who are contained in Page. immunoglobulins (see) and antibodies to them, complement (see), fibrinogen (see).

See also Synovial vaginas of sinews , Synovial bags .

Bibliography: Pavlova V. N. Synovial environment of joints, M., 1980, bibliogr.; The joints and synovial fluid, ed. by L. Sokoloff, N. Y. a. o., 1980; Kellner G. u. Klein G. Richtlinien zur Synovialzytologie, Z. Rheumat., Bd 35, S. 141, 1976; Naib Z. M. Cytology of synovial fluids, Acta cytol. (Philad.), v. 17, p. 299, 1973.

Century of H. Pavlova.